This invention concerns closure of incisions at the conclusion of many typical surgical procedures. Such closures can involve the rejoining of a wide variety of tissue types and bones, such as the rib cage, fascia, muscle skin and fat. Primary objectives of these closure procedures are to affect rapid and proper healing with a minimum of discomfort and scarring and to ensure that the wound remains securely closed. A related objective is that the closure not interfere with subsequent bandages and change of dressing.
Closure generally involves joining various layers of tissue, each in a special and correct manner. For instance, in abdominal surgery the severed peritoneum layer must be joined, followed by the layers of muscle, fascia, fat and skin. Additionally, retention sutures which pass through all layers may be used or required as insurance that the closure will not open. To accomplish these sutured closures typical materials include silk, gut and a wide variety of synthetics including Dacron.RTM., Teflon.RTM. and various new disposable materials. Depending on strength required, the material may be monofilament or braided and the caliber may be varied. Also there are metal sutures which are usually made from non-reactive stainless steel. Each material has characteristics which make its use appropriate for a specific purpose.
In all these techniques an important consideration is scar formation, the manner in which the human body reacts to suture materials which behave, for the most part, as foreign bodies and cause the body's defense mechanisms to seal them off with connective tissue. When the body's reaction is greater, more scar tissue will be formed.
Obviously, sutures cannot be passed without a delivery system which for these sutures consists of a large assortment of needles. Each type of needle is designed to provide a particular function, such as ease of handling, ease of passage, ease of release, minimal trauma, etc. The surgeon will generally either thread a needle or use pre-threaded suture-needle combinations and secondary instruments such as suture holders.
Wound closure is thus a major concern among surgeons whose primary objectives include: (a) to minimize time required to close, (b) to reduce surgeon fatigue and patient anesthesia time, (c) to reduce tissue trauma and accelerate wound healing, (d) to minimize blood loss, (e) to achieve optimum cosmetic results, and (f) to control and reduce overall costs.
It is these objectives which led to the development of a relatively new method of closure, namely joining adjacent tissue with metal staples delivered and secured by a staple gun. These metal staples which have partially replaced traditional sutures, have becomes popular for both external and internal closures, including joining cut ends of blood vessels, hollow organs and various layers of tissue within the body. Dozens of stapling devices for surgery have been developed by Americans and others, especially those of the Soviet Union.
One aspect of virtually all of these known stapling devices is the characteristic way in which they function and the use of bendable but non-resilient metal staples. Force is applied to change the initially open, generally U-shape configuration of each metal staple to a final, closed configuration, whereby the staple will hold two adjacent edges of tissue together. The staple devices are held and operated by the surgeon's hand, with force applied either manually by the surgeon or by a power-assisted mechanical force incorporated into the stapler. The force required to bend or crush the ends of the non-elastic metal staples is substantial, and is typically applied by a driver which drives each staple into position and then forcibly bends the legs of the staple. Once placed, the staples cannot be removed without the use of a separate device which forcibly returns the staple to its generally open configuration, so that removal is possible without tearing the tissue.
It is the broad purpose of this present invention to provide a surgical stapling instrument for joining with staples two opposing layers of tissue, skin and/or fascia of a patient. This device is to utilize a new type of elastic or spring staple and a unique delivery system, and to have a mode of increased control including reversible operation for removing an emplaced staple with the same device and without even moving the device from the site of placement. Another object of the present invention is to achieve a reduction in overall size and weight of the stapler in order to provide more exacting control for the surgeon, especially in difficult-to-reach places. A further objective is to reduce the amount of manual force and motion applied to the device when it is at the site or delivery point of the staple.
The new invention disclosed and claimed in subsequent sections of this application is fundamentally different from all known prior art stapling systems and devices, with typical of such prior devices being disclosed in the U.S. patents listed in the Appendix I attached hereto, and all relating to non-elastic staples which are crushed from open to closed condition.